The present invention relates to the art of fluid ejection devices and, more particularly, to inkjet printers which use a plurality of pens supported in a page wide array in a frame referred to herein as a printbar which extends across a path of movement of media on which printing is to take place. The individual pens used in this field usually comprise generally rectangular configured fluid containing housings of molded plastic or other suitable material so that a number of pens can be aligned end-to-end in the printbar. Maximization of the size of the pens for ease of manufacture and close positioning of the pens in the printbar without pen to pen contact is important for accurate ink drop placement and in keeping size of the printer footprint to a minimum. for these reasons it is considered particularly advantageous to utilize pens which have protruding fore and aft lower orifice array portions on opposite sides of the lower portion of the pen so that the pens can be aligned with the fore and aft portions of adjacent pens in a side-to-side or nested relationship. These pens are rotationally symmetrical about a vertical axis. Electrical interconnects comprising conductive contacts arranged in a pattern are provided on opposite sides of the pen and mating electrical contacts are mounted on the frame for engagement with the interconnects on the pens for transmitting power to control the ejection of fluid from the pens. The pens must be closely and accurately positioned without contacting each other and they must each be stabilized against linear and rotational movement in the spaces on the printbar in which they are mounted.
Microscopic fluid droplets are ejected usually downwardly from thermal or piezoelectric printheads onto media on which a print pattern is to be produced from orifice arrays or orifice plates mounted on the lower surfaces of the pens. The need for precise alignment of the pens relative to each other and to the frame or printbar on which they are supported is quite apparent to those skilled in the art.
The present invention therefore provides a method of positioning a fluid ejection device in a support to stabilize the device against movement in at least one direction relative to said support comprising urging said device into engagement with said support by biasing a surface on said device which protrudes from one side of said device to urge said device in said direction.
The present invention further provides a fluid ejection assembly comprising a frame and at least one fluid ejection device positioned in a mounting location on said frame, said device including a housing for containing fluid and having a positioning member laterally protruding from one side of said housing, said frame having a guide at said mounting location for receiving said member to guide said device into said mounting location in said frame.